When I was a kid there were only really two films that ever disturbed me. One was Watership Down, the other was When the Wind Blows.
The second just came into my head there, no idea why. When the Wind Blows was an animation that looked like a happy child's cartoon, about an innocent elderly couple who follow nonsensical government guidelines about how to protect themselves against a nuclear attack, as if they'll just be able to "see it through" like WW2. When a nuclear attack does actually happen, they alone survive because they've followed the guidelines, but slowly die of radiation poisoning in a blackened, ruined world.
Anyone remember this very bleak cartoon? It's been a long, long while since it's been on TV, maybe not in the last fifteen years. I wonder why that is. It's a powerful anti-nuclear film and should be shown again. Along with the TV series Threads (which hasn't been re-shown either, to my knowledge).